Thermal degradation of high‐temperature fluorinated polyimide and its carbon fiber composite

Abstract

High-temperature polymers are being used for a broad range of applications, such as composite matrices for structural applications (e.g., high speed aircraft). Polyimides are a special class of polymers that meet the thermal and oxidative stability requirements for high temperature composite aerospace applications. A weight loss study was performed on a fluorinated polyimide resin and its carbon fiber composite in an effort to determine its thermal stability and degradation mechanisms. Experiments were conducted using a preheated oven and thermogravimetric analysis to obtain the weight loss. Regardless of the method used, the resin and composite exhibited excellent thermal stability (less than 1% weight loss) below 430 C, regardless of 2-20 min of exposure. After 20 min of exposure at 510 C, the composite remained relatively stable with only 5.3% weight loss using the oven technique, whereas the neat polyimide sustained 12.6%. When degradation occurred, it was found to be the result of thermolysis and oxidation (to a lesser extent).

Kinetics of thermal degradation of polysulfone/polyimide blended polymeric membranes

“…Bormashenko et al14 worked on the thermal degradation of thermosetting and thermoplastic polymers induced by laser radiation and studied it by Fourier transform infrared (FTIR) spectroscopy. Adamczak et al15 studied the thermal degradation of high‐temperature fluorinated PI and its carbon fiber composites. Ren et al16 investigated the thermal degradation of the PI Fluorine‐containing polyimide (PIF2) synthesized from 4,4′‐(hexafluoroisopropylidene) diphthalic dianhydride and 4,4′‐diaminodiphenylmethane by high‐resolution pyrolysis gas chromatography/mass spectrometry, TGA, and FTIR spectroscopy.…”

Quantum Mechanical Computations and Microkinetic Modeling to Obtain Mechanism and Kinetics of Oxidative Degradation of a Polyimide

“…For example, fluorination of methylene carbon of MDA should thus prevent the oxidation of MDA, and similarly for the end‐caps. Fluorinated PMR variants are shown to have lower weight loss than the native polymers, in agreement with our conclusions.…”

Effect of fluorination on haze reduction in transparent polyimide films for flexible substrates

“…However, fluorinated side groups in 6FDA and TFDB can reduce the intra/intermolecular interactions, thus diminishes their yellow color problems. [9][10][11] During the continuous fabrication process of the FPI films, a poly(amic acid) (PAA) solution was cast on a belt and dried at 140 8C followed by a rapid temperature increase to 270 8C for thermal imidization to prevent the resulting films from being fragile and brittle. However, such a rapid increment in drying temperature causes film shrinkage attributed to a rapid gasification of residual solvents [such as dimethyl acetamide (DMAc)] leading to an appearance of haze features in the FPI films.…”